'93 C1500 Reverse Light Don't Work

I have a '93 C1500 W/T with a 4.3L and a 5-speed manual. The reverse lights do not work. The bulbs seem to fine. I am suspecting the reverse indicator swith on the tranny. Does anyone have any other ideas? How would I test this switch with my multi-meter? Thanks in advance for the help.

My first guess, if the bulbs are OK is the switch located on the transmission. It should be a relativly cheap part(around $15 or so), but if you REALLY want to check it, remove the switch from the trans, connect the leads from your multimeter to the connector on the switch. to check operation press in on the ball(it should be a ball type switch, anyway). If you can't do it with your fingers, you can press it into the floor, or some other hard surface. When the ball is depressed, it should make contact, and allow power to flow - no movement on the multimeter means a bad switch.

gl

The transmission switch is the culprit. I tested it and its circuit stays open no even when the ball is pressed in. One problem down, 3 to go.